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This algebra 2 math tutorial from NutshellMath offers targeted homework help on using trigonometric identities to evaluate other trigonometric functions. The instruction in this tutorial focuses on problems 1, 4-7 and 13-24 on pages 779 and 780 in the Algebra 2 text from Glencoe Mathematics. Trigonometric identities are fixed relationships between trig functions of general angles. In homework problems such as those covered, a value for a given trigonometric function can be used to solve for the value of a different trig function using these identities. While it is possible to use inverse trigonometric functions to find an angle measure, and then evaluate another function with that measure, using trigonometric identities to determine another trig function value directly has the benefit of not requiring approximation.
Some of the trigonometric identities are presented in this tutorial, though it is best to memorize them. One of the most important identities, which can be used to derive others, is the Pythagorean Identity. This identity states that the sum of the squares of the sine and cosine of an angle equals 1. Using this identity and its derivatives, it is possible to find many trigonometric function values given others.
To use trigonometric identities to find trig values from others, it is best to select a useful identity that contains both the known trigonometric function and the desired one, but no other unknowns. To find the unknown function value, simply plug in the known function value into the identity and solve for the unknown one algebraically. It is also helpful to remember the relationships between the trig functions, including the reciprocal functions. In cases where there isn't an identity in which both desired functions are in the same equation, it may be necessary to use two identities to first find other unknown values before solving for the desired function value. This method is very simple but quite effective in solving homework problems of this sort.
Since it is easiest to use an identity that contains both the known and unknown trig functions, it is best to memorize the trigonometric identities to have a complete set of problem-solving tools available. The instruction in this tutorial will help reinforce using these tools to solve homework problems.
This algebra 2 math tutorial from NutshellMath offers targeted homework help on using trigonometric identities to evaluate other trigonometric functions. The instruction in this tutorial focuses on problems 1, 4-7 and 13-24 on pages 779 and 780 in the Algebra 2 text from Glencoe Mathematics. Trigonometric identities are fixed relationships between trig functions of general angles. In homework problems such as those covered, a value for a given trigonometric function can be used to solve for the value of a different trig function using these identities. While it is possible to use inverse trigonometric functions to find an angle measure, and then evaluate another function with that measure, using trigonometric identities to determine another trig function value directly has the benefit of not requiring approximation.
Some of the trigonometric identities are presented in this tutorial, though it is best to memorize them. One of the most important identities, which can be used to derive others, is the Pythagorean Identity. This identity states that the sum of the squares of the sine and cosine of an angle equals 1. Using this identity and its derivatives, it is possible to find many trigonometric function values given others.
To use trigonometric identities to find trig values from others, it is best to select a useful identity that contains both the known trigonometric function and the desired one, but no other unknowns. To find the unknown function value, simply plug in the known function value into the identity and solve for the unknown one algebraically. It is also helpful to remember the relationships between the trig functions, including the reciprocal functions. In cases where there isn't an identity in which both desired functions are in the same equation, it may be necessary to use two identities to first find other unknown values before solving for the desired function value. This method is very simple but quite effective in solving homework problems of this sort.
Since it is easiest to use an identity that contains both the known and unknown trig functions, it is best to memorize the trigonometric identities to have a complete set of problem-solving tools available. The instruction in this tutorial will help reinforce using these tools to solve homework problems.